Background

Nasopharyngeal carcinoma (NPC) is a malignant tumor of the nasopharyngeal epithelium that exhibits an unbalanced geographical distribution [1]. In endemic regions, especially in South China, the worldwide age-standardized incidence rate of NPC is up to 25.39/100 000 person-years [2]. Among them, 4–10% of patients present with de novo metastatic nasopharyngeal carcinoma (mNPC), and the 5-year survival rate of mNPC is approximately 20% [3, 4]. According to the current National Comprehensive Cancer Network (NCCN) guidelines, platinum-based palliative chemotherapy (PCT) with or without locoregional radiotherapy (RT) is the cornerstone of treatment for patients with mNPC [5]. Many retrospective studies have asserted that cycles of PCT are not always positively related to survival and 4–6 cycles are recommended [31]. A phase I clinical trial of 27 patients with recurrent or metastatic NPC suggested that pembrolizumab treatment resulted in a median OS of 16.5 months. [32] Another phase II trial of nivolumab also suggested the potential use of immunotherapy for mNPC as the median OS of 44 patients receiving nivolumab was 17.1 months. [33] In addition to monotherapy, a phase I clinical trial from China demonstrated that the therapeutic effect of camrelizumab combined with chemotherapy was superior to that of camrelizumab alone [34]. The superior efficacy of the camrelizumab combination was recently confirmed in a phase III randomized study [35]. Therefore, how to use immunotherapy in addition to chemotherapy and radiotherapy to maximize the survival of patients with mNPC is worth further effort.

Our study had several limitations that should be mentioned. The source of patients who underwent PCT followed by RT was restricted to one hospital, and the sample size was not sufficiently large. As this study was retrospective in nature, selection bias and imbalances existed. Plasma EBV testing results were not available, although EBV was an important factor for therapeutic monitoring and prognostic evaluations. In addition, quality of life, late toxicity and some details on the following lines of therapy were not considered in this study. Thus, prospective studies are warranted to support our findings.

Conclusions

The real-world study suggests that concurrent chemoradiotherapy significantly improves OS compared with radiotherapy alone after palliative chemotherapy in patients with de novo metastatic nasopharyngeal carcinoma. More specifically, concurrent chemoradiotherapy with single-agent platinum after 4–6 cycles of chemotherapy can be considered.